1. Field of the Invention
The present invention is in the field of implantable weight control devices. More particularly, the present invention is directed to an intragastric balloon which has certain improved features enabling the balloon to be removed from the stomach noninvasively after a predetermined period of time has elapsed.
2. Prior Art
Gastric balloons used for achieving loss of weight in extremely obese persons have been known in the prior art. All gastric balloons utilized for this purpose function on the principle that an empty bag or balloon is placed into the stomach through the esophagus. Thereafter, the bag or balloon is filled (fully or partially) with a suitable insufflation fluid, such as saline solution, through a filler tube or catheter which is inserted into the stomach through the mouth or the nose. The balloon occupies space in the stomach thereby leaving less room available for food and creating a feeling of satiety for the obese person. Clinical experience of the prior art has shown that for many obese patients the intragastric balloons significantly help to control appetite and accomplish weight loss. Among the intragastric bags or balloons described in the prior art, one type remains connected to a filler tube during the entire time period while the balloon is in the stomach. The tube is introduced into the patient""s stomach through the nostrils. Such an intragastric balloon is described, for example, in U.S. Pat. No. 4,133,315.
A second type of intragastric balloon of the prior art is placed into the stomach with the assistance of an appropriate catheter having a removable, relatively rigid stylette disposed in the central lumen thereof. After deployment of the balloon within the stomach, the stylette is removed from the catheter and the balloon is filled with saline, whereafter the catheter is withdrawn from the balloon and the stomach. An intragastric balloon of the second type is described, for example, in UK Patent Application GB 2 090 747. The balloon of this UK patent reference, like many intragastric balloons of the prior art, is substantially spherical in configuration. It is necessary for such prior art balloons to become deflated through a deflation tube before the empty balloon may be removed from the stomach either by retraction through the esophagus, or by allowing the deflated balloon to pass through the digestive system.
To accomplish the foregoing, intragastric balloons of the second type are normally equipped with a self-sealing valve into which the filler tube can be inserted. One difficulty frequently encountered in the prior art is related to finding the valve when the balloon is already in the stomach and the surgeon is attempting to reinsert the filler tube for the purpose of adding or removing fluid from the balloon. Those experienced in the art will readily appreciate that a small endoscopic light which can be lowered into the stomach for the procedure causes the surface of the balloon to shine in such a manner that visually locating the valve is rather difficult and the process of searching for the valve undesirably prolongs the surgical procedure. Moreover, even after the filler valve has been visually located, it is often still difficult or awkward for the surgeon to reinsert the tube into the filler valve. This is because the balloon is slippery and positionally unstable. In other words, the usually spherical (or substantially spherical) intragastric balloons readily rotate in the stomach, so that even a slight disturbance of the balloon may place the filler valve into virtually any possible position relative to the filler tube poised to engage it.
Gau et al., in U.S. Pat. No. 5,084,061, discloses an intragastric balloon having an ellipsoid or like configuration so that the balloon implanted in the stomach tends to rotate or rock only about one axis when a surgeon attempts to manipulate the balloon, for example, for the purpose of finding a filler valve and inserting a filler tube into it. For easy location, the filler valve is disposed on the equator. A retrieval tab is mounted to the exterior of the balloon, to permit capturing of the balloon and retrieval from the stomach, after the balloon has been deflated and is no longer desired for weight control purposes. Visual and X-ray opaque markers are located in the proximity of the valve and of the retrieval tab to facilitate their visualization with an endoscopic light when the balloon is in the stomach. Although the device includes means adapted to facilitate removal of the balloon from the stomach after the balloon has performed its intended function, such removal requires an invasive intubation in order to deflate the balloon.
For further and detailed information regarding intragastric balloons and related inflatable bags or the like designed for implantation into the human body, reference is made to the following patents and/or patent applications: U.S. Pat. Nos. 4,416,267; 4,485,805; 4,311,146; 4,236,521; 2,470,665; 3,046,988; 157,343; Published PCT Application No. PCT/US79/00354, and UK Patent Specification No. 1333096. The following articles or publications are also of interest: xe2x80x9cIntragastral applizierter Ballon zur Behandlung der Adipositasxe2x80x9d, Deutsche Medizinische Wochenschrift (DMW), 1983, No. 8, page 315; xe2x80x9cIntragastraler Appetit-depressorxe2x80x9d, Balloon Munch. Med. Wochenschrift 124 (1982), No. 2, page 39; xe2x80x9cDer Magenballon in der behandlung der Adipositas permagnaxe2x80x9d, Deutsche Medizinische Wochenschrift, 1984 No. 31/32, page 1200; xe2x80x9cIntragastrick ballon som adipositasbehandlingxe2x80x9d, UGESKY. LEGER 144/6, February 1982, page 394; and the article by Joanne Richard titled: xe2x80x9cGastric bubble battles bulgexe2x80x9d. In light of the above-noted and other shortcomings of the prior art, there is a need in the art for an intragastric balloon which can be deployed and inflated within the stomach and can be non-invasively removed from a patient""s stomach after a predetermined period of time has elapsed. The present invention provides such an intragastric balloon.
It is a primary object of the invention to provide an inflatable intragastric balloon device that may be invasively deployed within the stomach of a patient, inflated and noninvasively removed from within the stomach after a predetermined period of time has elapsed.
The present invention provides an intragastric balloon that includes a deflation valve in a portion thereof. The deflation valve is a patch that has a bioabsorbable or biodegradable portion. The patch forms a portion of the wall of the inflatable intragastric balloon and is in leakproof engagement therewith. After the balloon has resided within the stomach for a predetermined period of time, the deflation valve becomes leaky due to disintegration of the bioabsorbable or biodegradable material comprising the patch and the balloon deflates within the stomach, thereafter to be passed through the patient""s digestive tract and excreted. The residence time of the balloon within the stomach depends upon the choice of biodegradable material incorporated into the patch and the detailed construction of the deflation valve.
The features of the invention believed to be novel are set forth with particularity in the appended claims. However the invention itself, both as to organization and method of operation, together with further objects and advantages thereof may be best understood by reference to the following description taken in conjunction with the accompanying drawings in which: